Retinal Caustic Optimization for Adaptive Vision Correction

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Solution Overview

Problem

Current methods for determining the required correction of ametropia in the human eye do not adequately account for the eye's physiology, particularly during accommodation, leading to suboptimal vision correction as they neglect the dynamic changes in refractive power and aberration structure.

Innovation Solution

A method that calculates the required optical correction by varying parameters within a search space to optimize the caustic of a light beam at the retina, using wavefront measurements and sub-metrics to determine an overall caustic metric, which ensures improved image quality across different viewing directions and accommodation states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional refraction methods (subjective or objective) are used to determine correction, then the refractive error can be measured, but the correction does not account for dynamic changes in accommodation state and aberration structure

Engineering Contradiction:
Improveadaptability to accommodation statesVSAvoidprecision of refraction determination
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by measuring wavefront aberrations across multiple accommodation states (e.g., different target distances) and using this dynamic information to determine the optimal correction. Instead of a single static measurement, the system captures how aberration structure changes with accommodation, enabling corrections that adapt to the eye's physiological behavior during viewing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter being measured from simple refractive error to comprehensive wavefront aberration parameters across multiple accommodation states. By measuring and analyzing higher-order aberrations and their variation with accommodation, the system identifies corrections that optimize retinal image quality across the dynamic range of viewing conditions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If full correction of higher-order errors is implemented in spectacle lenses, then vision correction improves for a specific viewing direction, but unacceptable distortions occur outside this correction range

Engineering Contradiction:
Improveprecision of aberration correctionVSAvoidacceptability across viewing directions
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by designing spectacle lenses with spatially varying optical properties that are optimized for specific viewing directions and accommodation states. Rather than uniform correction across the entire lens, the optical correction is tailored to match the local aberration characteristics for different gaze directions, maintaining image quality while avoiding excessive distortion in peripheral areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by selectively correcting certain aberration terms while leaving others uncorrected or partially corrected. The system identifies which higher-order aberrations contribute most to retinal image quality degradation and applies correction only to those terms, rather than attempting to correct all measured aberrations, thus avoiding the introduction of new distortions.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If subjective refraction is performed under daylight conditions with high-contrast optotypes, then refraction values are optimized for good lighting and high contrast, but the refraction is not suitable for night or twilight vision

Engineering Contradiction:
Improveprecision of refraction under test conditionsVSAvoidsuitability across lighting conditions
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent achieves universality by measuring wavefront aberrations under multiple lighting conditions (photopic, mesopic, scotopic) and using this comprehensive data to determine corrections that perform well across all conditions. The resulting spectacle lens or contact lens provides improved retinal image quality both during daytime subjective refraction testing and during nighttime viewing, making the correction universally applicable.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach provides a more comprehensive and adaptive vision correction that enhances image quality and depth of field, reducing fluctuations and improving the visual experience by optimizing the caustic of light beams at the retina, thus addressing the limitations of previous methods.

Implementation Method 1

The objective refraction is determined by determining the wavefront of a propagating light beam

Methodology Applied
Scientific EffectWavefront measurement:

Implementation Method 2

the ametropia of the eye can be approximately corrected by a lens with a toric surface

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

optimize the caustic of a light beam at the retina

Methodology Applied
Scientific EffectFocusing: Focusing

Data Source

PatentEP2173234B1Apparatus and method for determining the necessary correction of defective vision of an eye
Publication Date: 2016.04.06 CARL ZEISS VISION GMBH
  • EP2173234B1 patent drawingFigure 1~2
  • EP2173234B1 patent drawingFigure 3

AI summary

The invention relates to a method for determining the necessary optical correction (2) of the defective vision of an eye (1). According to the invention,the focal area (8) of a light beam (3) passing through the eye (1) is optimized in the region of the retina (6) of the eye (1) by means of optical correction (2). The invention further relates to an apparatus suitable for implementation of the method.